When joining the ends of lineal rails at the corners of structural sash and framing members of building windows, for example, the mitered corners of the lineal rails can be thermally welded to each other when the rails are of vinyl construction. Fiberglass-reinforced composite rails have many advantages over vinyl, but cannot readily be welded to each other. Mechanical joining has been used, increasing the cost of the framing corner and/or deleteriously affecting the sealing properties of the corner joint. One objective of the present disclosure is to provide the ability to weld the corners of a fiberglass-reinforced composite window or door framing to obtain the sealing benefits of a welded joint while retaining other benefits of using fiberglass-reinforced composites.
The present disclosure involves a number of aspects that can be implemented separately from or in combination with each other.
A framing corner joint in accordance with one aspect of the present disclosure includes first and second framing rails of fiberglass-reinforced resin construction. The first and second framing rails have hollow mitered ends. A pair of thermoplastic plugs are received in the mitered ends of the respective framing rails. Each of the plugs includes a body inserted into the hollow interior of an associated framing rail and a flat end wall at an angle of 45° to the body. The end walls extend outwardly from the peripheries of the bodies between the rail ends and have flat end faces that are bonded to each other. The bodies of the plugs preferably are hollow, and preferably are received by interference press-fit within the ends of the rails. Once inserted, the flanges of the two plugs preferably are welded to each other to join that corner of the framing member.